1. Field
The invention relates generally to internal combustion engines, and more particularly to a piston engine which runs smooth because energy is delivered to its crankshaft and stored in springs during the power stroke, and energy is delivered to the crankshaft during the exhaust stroke by the release of the spring's energy.
2. Description of the Prior Art
A standard four stroke, piston engine utilizes intake, compression, power, and exhaust strokes, and delivers power to the crankshaft during the power stroke of each cylinder. Therefore, in a one cylinder, four stroke engine, power is delivered to the crankshaft only one fourth of the time. In most typical, two cylinder, four stroke engines, the cycles of each cylinder are phased apart so that the power strokes of each cylinder occur at different times. As a result, power is delivered to the crankshaft only half of the time. In a conventional one cylinder, two stroke engine, power is delivered to the crankshaft only half the time, during the power/intake stroke. Engine vibration results from this sporatic power delivery in the three engines described above as well as high frequency fluctuations in vehicle speed, acceleration during the power strokes, and deceleration during the other strokes due to the load friction, and other loss factors.
One conventional remedy is to use a heavy crankshaft which acts as a flywheel or a flywheel itself, which, by its inertia, tends to keep the crankshaft speed constant. However, there are at least three problems with this system. First, the weight of the crankshaft or flywheel causes excess gas consumption, and makes the vehicle less manageable if it is otherwise light weight such as a motorcycle, motorized bicycle, or lawn mower. Second, the flywheel/crankshaft is not totally effective in maintaining engine speed. Third, it does not prevent the relatively low frequency engine vibration at the frequency of the crankshaft rotation in a two cylinder, four stroke engine or in a one cylinder, two stroke engine due to the sporatic power delivery to the crankshaft.
Another remedy is to build the engine with as many cylinders as strokes, and sequence the power strokes from each cylinder to provide one power stroke during each stroke. This system provides a more uniform power delivery to the crankshaft and so, less, low frequency vibrations and fluctuations in speed, but it is costly, heavy, and gas consumptive. Note that one cylincer, two stroke engines have less of a problem than one cylinder, four stroke engines because this two stroke engine has a power stroke during half of the cycle instead of one fourth in the four stroke.